U.S. patent number 6,251,540 [Application Number 09/006,057] was granted by the patent office on 2001-06-26 for composite electrode for electrochemical devices having a metallized glass or ceramic fiber current collector.
This patent grant is currently assigned to Lithium Technology Corporation. Invention is credited to Joseph B. Kejha.
United States Patent |
6,251,540 |
Kejha |
June 26, 2001 |
Composite electrode for electrochemical devices having a metallized
glass or ceramic fiber current collector
Abstract
A composite electrode for an electrochemical device wherein the
current collectors and carriers are incorporated into at least one
of the electrodes, which are used in alkali metal electrochemical
devices, and alkali metal-ion electrochemical devices, which
current collectors and carriers are a net of metallized glass or
ceramic fibers which may be plasma etched prior to metallizing, and
which are woven or non-woven.
Inventors: |
Kejha; Joseph B. (Meadowbrook,
PA) |
Assignee: |
Lithium Technology Corporation
(Plymouth Meeting, PA)
|
Family
ID: |
24912231 |
Appl.
No.: |
09/006,057 |
Filed: |
January 12, 1998 |
Related U.S. Patent Documents
|
|
|
|
|
|
|
Application
Number |
Filing Date |
Patent Number |
Issue Date |
|
|
724862 |
Oct 23, 1996 |
5750289 |
|
|
|
Current U.S.
Class: |
429/233; 429/237;
429/241; 429/245 |
Current CPC
Class: |
H01M
4/806 (20130101); H01M 4/745 (20130101); H01M
10/0565 (20130101); H01M 4/667 (20130101); H01M
4/74 (20130101); H01M 4/742 (20130101); H01M
4/668 (20130101); H01M 10/052 (20130101); H01M
4/382 (20130101); H01M 4/747 (20130101); H01M
2300/0025 (20130101); H01M 10/0525 (20130101); Y02E
60/10 (20130101); H01M 2300/0051 (20130101) |
Current International
Class: |
H01M
10/40 (20060101); H01M 10/36 (20060101); H01M
4/74 (20060101); H01M 4/66 (20060101); H01M
4/72 (20060101); H01M 4/80 (20060101); H01M
4/70 (20060101); H01M 004/64 () |
Field of
Search: |
;429/233,237,241,244,245 |
References Cited
[Referenced By]
U.S. Patent Documents
Primary Examiner: Kalafut; Stephen J.
Assistant Examiner: Wills; M.
Attorney, Agent or Firm: Seidel, Gonda, Lavorgna &
Monaco, P.C.
Parent Case Text
CROSS REFERENCE TO RELATED APPLICATION
This application is a continuation in part of my prior Application
Ser. No. 08/724,862 filed Oct. 23, 1996 now U.S. Pat. No.
5,750,289; Entitled: LIGHT WEIGHT CURRENT COLLECTORS AND CARRIERS.
Claims
I claim:
1. An alkali metal polymer electrochemical device wherein a coated
current collector is included in at least one of the electrodes,
which device includes a negative electrode, a polymer ion
conductive layer, and a positive electrode, wherein the current
collector consists of
a net of metallized glass fibers, with the metal selected from the
group consisting of nickel, copper, aluminum, and chromium.
2. An alkali metal electrochemical device wherein a coated current
collector is included in at least one of the electrodes, which
device includes a negative electrode, a polymer ion conductive
porous membrane with liquid electrolyte therein, and a positive
electrode, wherein the current collector consists of
a net of metallized glass fibers, with the metal selected from the
group consisting of nickel, copper, aluminum, and chromium.
3. An alkali metal polymer electrolyte electrochemical device
wherein a coated current collector is included in at least one of
the electrodes, which device includes a negative electrode, a
dielectric layer, and a positive electrode, wherein the current
collector consists of
a net of metallized glass fibers with the metal selected from the
group consisting of nickel, copper, aluminum, and chromium.
4. An alkali metal polymer electrochemical device as defined in
claim 1 in which said net is woven.
5. An alkali metal polymer electrochemical device as defined in
claim 1 in which said net is non-woven.
6. An alkali metal electrochemical device as defined in claim 2 in
which said net is woven.
7. An alkali metal electrochemical device as defined in claim 2 in
which said net is non-woven.
8. An alkali metal polymer electrochemical device as defined in
claim 3 in which said net is woven.
9. An alkali metal polymer electrochemical device as defined in
claim 3 in which said net is non-woven.
10. An alkali metal electrochemical device as defined in claim 1 or
2 or 3 in which said net is plasma etched before metallizing.
11. An alkali metal electrochemical device as defined in claims 1
or 2 or 3 in which an additional current collector is provided in
which said net is combined with said additional current
collector.
12. An alkali metal electrochemical device as defined in claim 2,
which device is an alkali metal-ion-electrochemical device.
13. An alkali metal polymer electrochemical device as defined in
claim 1 or 3, which device is an alkali metal-ion-polymer
electrochemical device.
Description
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention is directed to electrodes of electrochemical devices
which incorporate a woven or non-woven glass or ceramic fiber mesh
or net with a metallic coating thereon.
2. Description of the Prior Art
Electrochemical devices such as electric batteries of the solid
state type consist of at least an anode, a layer of electrolyte,
and a cathode. The batteries require a base current collector and
carrier for both the anode and the cathode. Various materials have
been proposed for use as the base current collector and carrier,
but none of them are entirely satisfactory.
Metallized plastic fiber nets do not possess optimal stiffness to
resist shrinkage after coating by active materials, which can lead
to curling and require additional calendering.
In addition glass or ceramic fiber nets of the same dimension, can
be made lighter than nets formed from plastic fibers.
In the U.S. Patents to Hope et al., U.S. Pat. Nos. 4,794,059;
4,861,690; and 4,960,655 carbon fiber and graphite material in the
form of a solid ribbon, or a woven or non-woven mesh are described
which are used as base current collectors and carriers. While
graphite and carbon in solid ribbon or mesh form are satisfactory
for their intended purpose, the carbon fiber non-woven fabric is
usually of 4 mils thickness, is heavier than polyethylene and other
plastics, and also costs more than is optimal. Since the base
current collector and carrier often account for as much as 50%
(percent) of total battery weight, a reduction in the weight is
desirable and will also increase the energy density of the
battery.
In Japanese Patent No. 58-61566 (a) a production method for a lead
storage battery is described where a lattice structure of synthetic
resin with a cross-section of circular shape is immersed in melted
lead so as to form a thin lead film on the surface of the lattice
structure. The disclosed resin material is polyproproplene, this
structure is restricted to lead batteries, and would not be
suitable for use in other electrochemical devices as described by
applicant.
In Japanese patent No. JA-7303501-R an electrode grid for lead
accumulators is described which comprises a plastic film with
holes, that has been coated by vacuum and electroplating of lead on
the plastic film. This structure is only useful with lead
batteries, and not suitable for other electrochemical devices as
described by applicant.
In Japanese Patent NO. 55-39180 (A) a method of production for the
electrode base of a cell is described. A porous member such as felt
or unwoven cloth of polypropylene, or polyethylene is immersed in a
binder solution that contains conductive powder such an nickel,
iron, or carbon powder. The porous member is dried and
non-electrolyte and electronic galvanization with nickel are
non-electrolyte and electronic galvanization with nickel are
performed to obtain a nickel layer on the member. This does not
suggest the structure as described by applicant. The whole Japanese
patent structure including powder is metallized after coating,
while applicant only metallizes the fibers, which are of a
different material than the Japanese patent.
In the German patent No. DT 2721560 expanded metal grids used as
lead accumulator plates are described. The grids are made from a
strip of stiff lead-antimony alloy or plastic resistant to H.sub.2
SO.sub.4, which is coated on one or both sides with a rolled sheet
or strip of lead-antimony, which is then made into expanded metal
in the conventional manner. This structure is not suitable for use
in other than lead acid batteries, and does not suggest applicant's
structure which is used in other than lead acid batteries.
In the U.S. Patent to Drews et al., U.S. Pat. No. 5,139,902, an
electrode is described which comprises a grid plate, which serves
as the carrier for battery active material and for current supply
and return. The grid plate includes woven plastic threads which are
rendered electrically conductive by coating with a conductive layer
of metal, and additionally metallized by coating with at least one
coating of a lead-tin alloy or lead alone. The grid plate is
further divided into two dimensional zones for storage of the
active material, and current conducting zones for current supply
and return. This plate which is described as having a thickness of
4 mils to 1/8 inch is useful only for lead acid batteries, and does
not suggest the structure described by applicant.
In the U.S. Patent to King et al., U.S. Pat. No. 4,129,692 an
electrode structure for an electrochemical cell in lead acid
batteries is described, which is a fibrous support of organic
polymeric material of a thickness of 0.1 to 3 mm, which has a
pattern of solid conductors thereon, which extend over the surface
of the porous support from current take-off regions to spaced
regions, with electrochemically active material deposited on the
fibrous material, which has had metal deposited thereon or wires to
provide the electrical conductors. This structure is much thicker
than applicants'. In addition, the King et al. structure is
intended for use with lead acid batteries, and would not be
suitable for the structures described by applicant.
SUMMARY OF THE INVENTION
It has now been found that a composite electrode for
electrochemical devices, which uses a current collector having
metallized glass fibers or ceramic fibers which are woven or
non-woven, provides a structure of lighter weight than similar
structure with metalized plastic fibers, possesses the required
current collecting capability, which is stiff, resistant to
shrinkage, has a long operating life, increases energy density,
reduces the weight considerably, is economical, is suitable for
mass production and provides numerous other benefits.
The principal object of the invention is to provide composite
electrodes for electrochemical devices which have metallized glass
or ceramic fiber current collectors, are strong, lightweight,
inexpensive, resistant to shrinkage, and which fiber current
collectors are not reactive with the components of the
electrochemical devices.
A further object of the invention is to provide composite
electrodes of the character aforesaid that are suitable for mass
production.
A further object of the invention is to provide composite
electrodes of the character aforesaid that are simple and
inexpensive to construct.
A further object of the invention is to provide composite
electrodes of the character aforesaid that are useful with a wide
variety of electrochemical devices.
A further object of the invention is to provide composite
electrodes of the character aforesaid which help to improve the
energy density of the electrochemical devices into which they are
incorporated.
A further object of the invention is to provide composite
electrodes of the character aforesaid which have current collectors
which are of lighter weight than plastic net current
collectors.
Other objects and advantageous features of the invention will be
apparent from the description and claims.
BRIEF DESCRIPTION OF THE DRAWING
The nature and characteristic features of the invention will be
more readily understood from the following description taken in
connection with the accompanying drawing forming part hereof in
which:
FIG. 1 is a diagrammatic view of a composite electrode having a
metallized glass or ceramic fiber current collector, and
FIG. 2 is a view similar to FIG. 1 with an additional
collector.
It should, of course, be understood that the description and
drawings herein are merely illustrative and that various
modifications and changes can be made in the structures disclosed
without departing from the spirit of the invention.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring now more particularly to the drawing a typical
electrochemical device such as an alkali metal-polymer battery 10
is illustrated, which incorporates the composite electrode 11 of
the invention.
Alkali metal-polymer batteries such as alkali metal or alkaline
earth metal-polymer batteries, and alkali metal-ion-polymer
batteries, and for example lithium polymer batteries, or
lithium-ion-polymer batteries, consist of at least an anode or
negative electrode, a polymer ion-conductive layer, and a cathode
or positive electrode. Such batteries can be of virtually any
desired size and configuration, and usually include additional
layers such as current conducting backing layers, insulating layers
and connection layers. In batteries with liquid electrolytes, the
polymer is replaced by a porous membrane containing liquid
electrolyte.
For purposes of illustration, the alkali metal battery 10 to be
described is of the lithium metal type, but other alkali metal or
alkaline earth metals can be used if desired.
The electrode 11 as illustrated includes a non-woven glass fiber
current collector which has a plurality of holes 14 therein.
The net 12 is preferably plasma etched, and is coated by any well
known method for metallizing such as vacuum vapor deposition,
magnetron sputtering, or electroless metal plating, or metallized
by the described methods and electroplated, which coating 16 is of
metal, which is selected to be compatible with the battery
chemistry and components. The coating 16 may be on one or both
sides of, or may completely encapsulate, the net 12. The coating 16
supports the specific current collecting and carrying capabilities
as required by the device in which it is incorporated, with a
metallized coating of copper, aluminum, nickel, or chrome being
particularly suitable.
The coating 16 does not close the holes 14, which holes can take up
to approximately 90% (percent) of the surface area of the net
12.
The net 12 for a piece of 2.times.3 inches size non-woven glass
fiber weighs 0.04 g, while the same thickness of non woven
polyester would weigh approximately 0.10 g.
Since the net 12 is used in a cathode, it is coated with additional
layers 18 of cathodic composition of well known type, which may
have finely ground particles of an intercalation compound such as
vanadium oxide compound V.sub.6 O.sub.13, mixed with an organic
solvent, polymer, alkali salt, and carbon black.
The resultant cathode 11 has the current collector 12 embedded in
the described composition matrix. Additional layers may be applied
to form the complete electrochemical device. The layer 18 may have
a layer 19 of polymeric electrolyte applied thereto which may be a
thin layer of polyethylene oxide compounded with a lithium
salt.
The layer 19 may have an anodic layer 20 applied thereto which may
be an alkali metal foil or alkali metal alloy foil.
Layer 20 may optionally have a metallized expanded or perforated
plastic film 21 added on top thereto as a current collector. If
only one side of film 21 is metallized, then the metallized side
should face layer 20.
If it is desired to construct a lithium-ion battery, the anode is
of similar construction as the cathode 11, except that the oxide
compound is replaced by a carbon compound.
The metal selected for coating should be compatible with the
particular chemistry of the battery. For example in lithium
batteries, copper is the preferred metal for the anode, and
aluminum is preferred for the cathode.
For other types of batteries, capacitors or fuel cells, appropriate
chemistry layers may be applied on described current
collectors/carriers. It should be noted that capacitors include a
dielectric layer between electrodes.
The net 12 may also be of metallized ceramic fibers of well known
type, such as zirconium, or other materials, having similar
properties as the illustrated glass fibers.
In addition the glass or ceramic fiber nets may be combined with
other metalized fiber collectors or metal grids, foils or metalized
films to provide ultra high rate capability multiple collectors.
such as with collector 22, in the cell 23 as shown in FIG. 2.
It will thus be seen that structures have been provided with which
the objects of the invention are achieved.
* * * * *